Note that the author is a columnist for the Washington Post who is well known for his radically left-wing views (he’s probably to the left of Bernie Sanders). One expect he would revile Trump, or any Republican, for that matter. Asking him what he thinks about Trump would be like asking Hitler what he thinks about Jews, and while the answer wouldn’t tell you much about Jews, it would tell you a great deal about Hitler.
As someone with no experience in public office, it isn’t surprising that Trump isn’t much for positions, and that he is more focused on style and rhetoric. In many ways he is reprising his role from his TV show. Clinton has settled positions, and liberally changes them depending on her most recent polls and focus group. If you want a consistent ideological position based on principles, consider supporting Johnson (Libertarian) or Stein (Greens).